Elevator position indicator



Feb. 22, 1949. J. R. SCHOENBAUM ELEVATOR POSITION INDICATOR 2She'ets-Sheet l Filed June 5, 1946 Feb. 22, 1949. J, R SCHOENBAUM2,462,781

ELEVATOR POSITION INDICATOR Filed June 5, 1946 2 Sheets-Sheet 2 INI/ENT"MM QM JOEPH RSCHOE. AUM.

Pnenxed Feb. 22, 1949 ELEVATOR POSITION INDICATOR Joseph R. Schoenbaum,Roseland, N. J., assignor to William Martin, Jr., doing business asMartin Elevator Company, New York, N. Y.

Application June 5, 1946, Serial No. 674,604

4 claims. l

This invention relates to elevator systems and. more particularly, toposition indicators for such systems.

It is a general object of the invention to improve the construction andoperation of elevator systems and position indicators therefor.

It is a more specific object of the invention to provide a low costindicator system which is readily installed, simple in construction andoperation, and in which the parts are readily interchangeable.

It is a still more specie object of the invention to provide, first, anelevator system comprising a position indicator in which no moving partsare necessary and, second, a position detector having no wearing parts,thus eliminating difficulties heretofore experienced due to mechanicalwear of the moving parts used in the indicators and position-detectingmeans.

It is a further object of the invention to provide anelectrically-operated indicator system in which a minimum of conductorsare utilized for connecting the position detecting means to therespective indicators.

It is a still further object of the invention to provide a positiondetecting device which is mechanically connected to a drum or otherconvenient part of the elevator drive mechanism, such detecting deviceproducing a voltage which is dependent upon lthe position of the car inthe shaft. An additional object is to utilize such voltage forenergizing a plurality of visual indicators each comprising a gas-lledglow tube, one of which may be conveniently placed at each floor levelor at any other suitable location, each glow tube having an illuminatedcharacter or series of characters for indicating the position of the carin the shaft.

Another object of the invention is to provide such an indicator in whichthe characters are illuminated in ascending order as the car rises inthe shaft and in descending order as the car is lowered.

Various other objects, features and advantages of the invention willbecome apparent from the following detailed description taken inconnection with the appended drawings, in which- Figure 1 is a vertical,sectional view of an elevator system utilizing the novel positionindica- I'fOlS Fig. 2 is a front elevational view of an elevatorposition indicator having a suitable energizing circuit associatedtherewith;

Fig. 3 is a vertical sectional view of the indicator shown in Fig. 2;

Fig. 4 is a sectional view taken along the line 4--4 of Fig. 3; and

Fig. 5 is a fragmentary perspective view of an electrode and thecharacters supported thereby.

In accordance with the invention, a position detecting means P, which,in the example shown, includes a rotary transformer mechanicallyconnected to the elevator drive mechanism, is utilized for providing avoltage which varies in accordance with the position of the elevator carin the shaft. The output voltage from the position detector is fed to aplurality of novel indicators I, one of which is preferably provided foreach floor level or in other locations as desired. The preferred form ofindicator comprises an elongated gas-lied glow tube which includes anumber of characters, such as letters or numerals, which are illuminatedin accordance with the position of the car in the shaft.

Referring to the drawings in detail and particularly to Fig. 1, theelevator system may comprise an elevator shaft I0 in which a car II issuspended. The car I I is provided with the usual cable l2 -to which isattached a counterweight I3 for partially balancing the weight of thecar. The drive mechanism for the elevator system may include the cableI2 which is secured to the car as at I5, said drive cable passing oversuitable pulleys I6 at the top of the shaft and thence downwardly to adrum I1 which may be mounted below the bottom iloor of the building orat the top of the shaft depending on the type of installation. The drumis mounted on a shaft I8 which is driven, in any suitable manner, by amotor I8.

The position detecting means P comprises a rotary transformer 25 havinga rotor ZIE and a stator 2l, Fig. 2. The rotor is mechanically connectedto the drum shaft I8 or any other suitable moving part of the elevatordrive mechanism as through reduction gearing 21a. In the embodiment ofthe invention shown in Fig. 2, the stator 2l comprises ytwo sets oflaminations or core members 28, 28 and 29, 29 which are offset at anangle of 90 degrees from each other. A pair of series-connected primarywindings 33 are mounted on the laminations 28 and a pair ofseries-connected primaiy windings 3| are mounted on the laminations 23.The windings 30 are connected between an input terminal 32 of a suitablealternating current source and a stationary up contact of a double pole,double throw relay 34. The windings 3| are connected between the inputterminal 32 and a stationary down contact of the relay 34. A movablerelay contact 35, which is adapted to contact the down and up contactspreviously described, is connected to the other terminal 38 of thealternating current source. It will be apparent that the windings 30 areenergized when the relay contacts are in the up position while thewindings 3| are energized when the relay contacts are in the "down"position. The relayv 34 is connected to and usually forms a part of theconventional elevator control board, this relay being energized by asolenoid coil 39 to move the contacts to the up position as the carstarts to rise in the shaft and to move the contacts to the down"position when lthe car starts to descend.

A secondary winding 40 is mounted on the rotor 26, said winding beingconnected between an electrode conductor 4| of the indicator I and amovable contact 42 of the second set of contacts provided on relay 30.The stationary up and down contacts associated with movablecontact 42are connected by conductors 43 and 44, respectively, to electrodes ofthe indicator I in the. manner hereinafter explained.

The rotor is preferably mechanically conaseavsi f nected to the drivemechanism so as to rotate through an angle of approximately 90 degreesas the car moves from the bottom to the top of the shaft. With the carat the bottom of the shaft, the up contacts are closed and thelongitudinal axis of the rotor is perpendicular to the axis of windings3|), as shown, with the result that the transformer operates at minimumefficiency, only a very small voltage being induced in the secondarywinding by the energized primary windings 30. As the car rises in theshaft, the rotor turns to thereby increase the coupling between thewindings 30 and 40, thus raising the output voltage of the transformer.As the car reaches the top of the shaft, the maximum output voltage isdeveloped and the longitudinal axis of the rotor coincides with the axisof the windings 30. Subsequently, when the car descends, the relaycontacts move to down position, deenergizing primary windings 30 andenergizing primary windings 3|. In /this manner, the output voltageagain falls to a minimum since minimum coupling is provided between thewindings 3| and 4|) with the rotor in the last described position. Asthe car descends, the rotor returns toward its original position, thusincreasing the coupling between windings 3| and 40 and raising theoutput voltage of the transformer, the maximum voltage being reachedwhen the car returns to the bottom of the shaft. Consequently, as thecar moves from one end of the shaft to the other in either direction,the output voltage of the transformer has a minimum value when the caris in its initial position at one end of the shaft which rises to amaximum value as the car moves toward the other end of the shaft. Itwill also be apparent that the output voltage is proportional to thedistance of the car from the bottom of the shaft when the car is movingupwardly and that vsaid output voltage is proportional to the 4 distanceof the car from the top of the shaft when its is moving downwardly.

The output voltage, in accordance with the invention, is used to actuateone or more position indicators I which show the position of the car` inthe shaft and the direction in which the car is moving. The indicator,which is best shown in Figs. 2 and 3, comprises an elongated glow tube50 which is lled with an inert gas or combination of gases such, forexample, as neon or argon. The tube is mounted between top and bottommetal brackets 5| and 52, respectively, which, in tnrn, are secured inany suitable manner to\a panel or support 53. A rod 54 carrying aninterior electrode 55 extends through a seal 55 at the bottom of thetube and this rod is suitably secured to the bracket 52 which iselectrically connected to the conductor 43. In similar fashion, a rod 51carrying an interior electrode 58 extends through a seal 59 at the topof the tube and said rod 51 is secured to the bracket 5|' which iselectrically connected to the conductor 44.

An indicator electrode or conductor rod 60 is mounted on the bracket 52and insulated therefrom as by an insulating washer 6|. From the bracket52, the indicator electrode extends through the seal 56 and thenceaxially through the tube to the top thereof where it is shaped to form acircular segmental portion which, together with the electrode 58,defines a top discharge gap 62. The lower portion of the indicator rodand the electrode 55 denne a bottom discharge gap 63. The electrode 60is connected, in any suitable manner, to the conductor 4| so that, whenthe relay 34 is in the up position, the output voltageof the transformer25 is im- A pressed across the lower discharge gap 63 and,

when the relay is in the down position, the output voltage is impressedacross the upper discharge gap 62. A

In order to indicate the position of the car in the shaft, a series ofcharacters 65 are provided which may be of any suitable type, asletters, numerals or otherwise, as desired, so as to indicate thevarious levels or sublevels of the building. Each character may beformed of conducting material if, in a particular application, it isldesired that the characters glow in indication of the car position;further said characters may be coated with an activatable material suchas is known to the art as a uorescent substance, to provide an increasein luminous intensity; further said characters may be made ofnon-conducting material if, in a particular application, it is desiredthat the characters be outlined or silhouetted against a glowing portionof the tube. The support 66 may conventiently extend through or bewelded to the rod 6U in order to properly support and position thecharacter within the glow tube.

The operation is as follows: Assuming that the car is at the bottom ofthe shaft and the contacts of relay 34 are in the up position, a smallvoltage is applied to the lower discharge gap G3 causing the gas in thelower portion of the tube to become luminescent. As the car rises, thevoltage applied to the gap 63 increases with resultant increase in thelength of the glowing portion of the tube. When the car reaches the topof the shaft, the maximum voltage is applied and the tube is completelyluminescent. As the top of the glowing column of gas successivelyreaches the ends of the suports 66 on characters 65, the gas surroundingsaid characters becomes luminous to thereby indicate the position of thecar. The transformer windings and character arrangement are so adjustedthat the characters become luminous in ascending order as the carreaches the corresponding floor levels indicated thereby.

When the car reaches the top of the shaft, the contacts of relay 34 moveto the down position, thus deenergizing the lower discharge gap 63 andapplying a small voltage across upper discharge gap 62. As a result, thegas within the tube ceases to glow except for a small portion at the topof the tube adjacent the upper discharge gap 62. As the car descends,the voltage impressed upon the gap B2 increases with the result that endof the glowing column of gas moves downwardly, thus illuminating thecharacters 65 in descending order until the car reaches the bottom ofthe shaft. Thereupon, the relay 34 again moves to the up position inreadiness for another cycle of operation. It will be understood that theindicator functions properly when the car changes direction at anintermediate floor level since the relay 34 operates whenever the carchanges direction and the output voltage of the transformer is dependentupon the position of the car in the shaft.

In Figure 1, a separate indicator is shown at each floor level. It willbe understood that the corresponding electrodes for each indicator maybe connected in parallel as by a cable 10, the output of the transformerbeing ample to energize any desired number of indicators. In thismanner, the three-wire cable is the only connection required between theindicators which is a considerably simpler arrangement than provided byindicating systems previously known. Moreover, indicators may be placedin any position desired and even in positions quite remote from theelevator without the necessity for providing bulky and expensivemechanical connections therefor.

The present system has been found to be eX- tremely reliable inoperation and ready interchangeability of parts is possible since anindicator may be removed simply by physically removing the tube from itssupporting b rackets. It will also be apparent that a completelyelectrical system is provided with no mechanical parts to wear out onthe indicators.

Although the invention has been described in connection with a presentpreferred embodiment, it will be understood that various changes andmodifications may be made without departing from the spirit and scope ofthe invention. Thus, the tube may be surrounded by a sleeve havingcutout portions to represent the characters lindicating the floorlevels, these cutout portions being illuminated when the gas is glowingin the adjacent portions of the tube. Also the tube may be curved orotherwise formed to suit a particular design. Hence, it will be apparentthat the form of characters shown is merely illustrative and otherconstructions may be used to furnish the visual floor-level indication.It is also within the scope of the invention to utilize a tube havingonly a single pair of electrodes which are energized by a voltageproportional to the height of the elevator in the shaft. In such amodification, the height of the glowing gas column indicates theposition of the car in the shaft at all times although it is notpossible to determine whether the car is ascending or descending when itis stationary in the shaft. All the above modifications together withothers which may occur to those skilled in the art are intended to becovered in the appended claims.

The invention as hereinbefore described referred to a rotary transformerfor producing the variable voltage. It shall be understood, however,that the invention is not to be thus limited.

Thus, for example, there may be utilized any intended therefore in theappended claims to cover all such changes and modifications.

What is claimed as new and desired to be secured by Letters Patent is:

1. In an elevator system, in combination, a car in an elevator shaft, adrive mechanism including a rotatable member for raising and loweringthe car in said shaft, a rotary transformer having a rotor and a stator,said rotor being mechanically coupled to said rotatable member wherebythe,

transformer output voltage is dependent upon the position of the car inthe shaft, and an elevator position indicator comprising an elongatedgasfilled glow tube, an electrode structure defining a discharge gap ateach end of the tube, means for applying said output voltage across oneof said discharge gaps to cause the gas within the adjacent portion ofthe tube to glow, the length of the glowing portion depending upon themagnitude of said voltage, and a plurality of indicators spaced alongthe tube, each indicator registering when the gas in the adjacentportion of the tube is luminescent.

2. In an elevator system, in combination, a car in an elevator shaft,variable transformer means for producing a voltage which is dependentupon the position of the car in said shaft, an elevator positionindicator comprising an elongated gasfilled tube, an electrode structuredefining a discharge gap at each end of the tube, means for applyingsaid transformer output voltage to one ldischarge gap while the elevatoris ascending and to the other discharge gap while the elevator isdescending, and indicating means responsive to the energization of saiddischarge gaps, said indicators showing the position of the car andwhether it is ascending or descending.

3. In an elevator system, in combination, an elevator shaft, an elevatorcar therein, a drive mechanism for raising and lowering the car in saidshaft, a current source, an electrical translating device connected tosaid current source and actuated by said drive mechanism for producing arst voltage proportional tu the distance of the car from the bottom ofthe shaft and a second voltage proportional to the distance of the carfrom the top of the shaft, an elongated glow tube having two sets ofelectrodes, one adjacent each end thereof, a circuit for impressing saidfirst voltage on one set of electrodes, a circuit for impressing saidsecond voltage on the other set of electrodes, means for selectivelyenergizing said circuits responsive to the direction of movement of thecar in the shaft, and indicating means responsive to the energization ofsaid electrodes, said indicators showing the position of the car andwhether it is ascending or descending.

4. In an elevator system, in combination, an

elevator shaft, an elevator car therein, a drive mechanism including arotatable member for raising and lowering the car in the shaft, anelectrical transformer having a rotor element mechanically coupled tosaid rotatable member and a stator element, one of said elements havingtwo windings thereon defining an angle of 90 degrees therebetween, acurrent source for energizing said transformer, an elongated glow tubehaving two sets of electrodes, one adjacent each end thereof, a pair ofcircuits connecting said windings with the respective sets ofelectrodes, means for selectively energizing said circuits responsive tothe direction cf movement of the car in the shaft, and indicating meansresponsive to the energization of said electrodes, said indicatorsshowing the position of the car and whether it is ascending o'rdescending.

JOSEPH R. SCHOENBAUM.

REFERENCES CITED The following references are of record in the flle ofthis patent:

UNITED STATES PATENTS Number Name Date 1,135,014 Harding Apr. 3, 19151,554,915 Hewlett et al Sept. 22, 1925 2,013,012 Tauschek Sept. 3, 19352,390,415 Bailey et al.- Dec. 4, 1945 FOREIGN PATENTS Number CountryDate 250,922 Great Britain Aug. 26, 1926

